Is irradiation safe? Proponents insist it is; opponents argue it is not. Here is a summary of the positions of proponents and opponents on safety and other issues related to irradiation.
Unique Radiolytic Products
Irradiated foods contain certain compounds that are formed when the food is subjected to high-energy ionizing radiation, such as gamma rays or X-rays. The FDA has estimated that the concentration of radiolytic products formed in food treated at a dose of 1 kilogray is on the order of 3 parts per million.
Proponents
Any food undergoes changes when it is treated, whether that treatment involves boiling, baking, or irradiating. Ac cording to information prepared by the Atomic Industrial Forum (a group that favors nuclear energy), one study of radiolytic prod ucts in highly irradiated meat “concluded that there are actually no such things as unique radiolytic products (or URPs).”1
The American Dietetic Association posi tion paper on irradiated foods states: [F]ree radicals and other compounds produced dur ing irradiation are identical to those formed during cooking, steaming, roasting, pasteurization, freezing, and other forms of food preparation… All reliable scientific evidence, based on animal feeding tests and consump tion by human volunteers, indicates that these products pose no unique risk to human beings.”2
One study in India concluded that there was greatly increased incidence of polyploidy, or chromosomal damage, in a group of children fed irradiated wheat as compared to a control group. Supporters of irradiation, however, challenge this study’s results as non-reproducible.
Opponents
Such scientific studies that have been done to date do not support the safety of food irradiation, critics say. In fact, the FDA’s own statement on irradiation acknowledges that “current state-of-the-art toxicity tests are not sensitive enough to detect the potential toxicity of URPs at low levels.”3 Of the 441 studies that had been done on the subject at the time of the FDA’s review, all but five were judged by the review team to be “inadequate to evaluate the safety of irradiated food.”4 Of those five, the New Jersey School of Medicine Department of Preventive Medicine and Community Health determined two “to be methodologically flawed, either by poor statistical analysis or because negative data were disregarded. One of the two also suggested that irradiated food could have adverse effects on older animals. In a third FDA-cited study, animals fed a diet of irradiated food experi enced weight loss and miscarriage.”5
Richard Piccioni, Ph.D., senior staff scien tist at Accord Research and Educational As sociates, Inc., has noted: “Without toxico logical testing at exaggerated doses, the carcinogenic risk to large human populations ingesting any additive or residue is impossible to assess.” Contrary to proponents’ claims that URPs, if they exist, are safe, Piccioni writes: “the available scientific literature pro vides evidence to make a strong presumption of carcinogenicity in some if not all irradiated foods.”6
Public Citizen’s Health Research Group noted that the FDA’s review of scientific literature did not include one carried out under auspices of the USDA: “This study, which was actually 12 different studies, examined the effect of feeding irradiated chicken to several animal species. One of these 12 studies found that fruit flies fed irradiated chicken had a statistically significant dose-related increase in the rate of death of their offspring compared with flies who were not fed irradiated chicken.”
Another study cited by Public Citizen found that “mice fed irradiated chicken had a greater incidence of kidney disease than mice fed unirradiated chicken.”7 Other published studies cited by Public Citizen found kidney damage and testicular damage in rats fed irradiated chicken.
Background
Irradiation has been shown to reduce the vitamin content of food.
Proponents
The International Consultative Group on Food Irradiation says, “Just as vitamins vary in their sensitivity to heat, so do they vary in their sensitivity to radiation…. Vitamins A, F, C, K, and B-1 (thiamine) in foods are relatively sensitive to radiation, while some other B vitamins such as riboflavin, niacin, and vitamin D are much more stable.”8
The American Dietetic Association says, “The relative sensitivity of different vitamins to irradiation depends on the food source, and the combination of irradiation and cook ing is not considered to produce losses of notable concern.” In any case, steps can be taken to minimize nutritional losses in the irradiation process, including “irradiating food in an oxygen-free environment or in a frozen state.”9 (Neither of these proffered mitigating techniques has been put into rou tine practice at any irradiation facility in the world.)
Still, there are some who insist irradiation has no impact or, indeed, may have a positive one on the nutritional content of food. The most extreme statement of this view is made by the Atomic Industrial Forum: “In virtually all cases, food preserved with radiation is nutritionally equal or superior to those preserved by other comparable means. Proteins and essen tial amino acids are not destroyed and, in some cases, more vitamins are retained.”10
Opponents
“Irradiation … reduces levels of essential nutrients in food, especially vitamins A, C, F, and the B complex. Cooking irradi ated food reduces these levels still further. The industry reluctantly admits this but suggests that the problem could be taken care of by vitamin supplements!” write Michael Colby, director of Food & Water, Inc., a non-profit organization established to protect food safety, and Samuel S. Epstein, a professor of occupational and environmental medicine at the University of Illinois Medical Center Chicago.”12
The extent of nutritional loss varies with the type of food and the radiation dose, writes Susan Meeker-Lowry. “Generally, the more complex the food, the less it suffers. Still, a 20 percent to 80 percent loss is not uncommon.”
Background
Treatment by irradiation does not visibly harm the fruit, as, say, treat ment by hot-water does.
Proponents
Fruits that have been irradiated look better and have a longer shelf life than untreated fruits or fruits that are treated by other means. Irradiation “will extend shelf life for most foods at competitive costs.”13 An article in Food Technology claims irradiation “extends shelf life of the fruit by delaying maturation… and inhibiting mold growth on the fruit.”14
Opponents
Claims of increased shelf life are not proven for Hawaiian produce. Lyle Wong of the state Department of Agriculture, one of irradiation’s chief proponents, has said: “I’m not sure if irradiation as a commodity treatment will give rise to a better product.”15 Irradiation can cause fruit to become scalded and unsuitable for marketing. Indeed, the state Department of Agriculture has paid to cover the $700 cost of irradiating a shipment in 1995 where the fruit was of such poor quality that the wholesaler would not accept it.”16
Background
The chief – and, so far, only- reason cited for supporting construction of an irradiation facility in Hawai’i is to increase the volume of fruit exported to the mainland United States.
Proponents
Exports having a potential value of as much as $300 million a year are being lost to Hawai’i because of the U.S. Department of Agriculture’s fruit-fly quarantine on shipments of Hawai’i produce to the U.S. main land. With the USDA ready to approve a generic irradiation dose for all fruits that are host to fruit flies, the way is clear to tapping this market.
In addition, test marketing of Hawaiian fruit irradiated in Chicago has been hugely successful, showing widespread consumer acceptance of irradiated fruit.
Opponents
Even the state Department of Agriculture has acknowledged that the “$300 million figure for exports is subject to debate.”17 No economic analysis has been pro duced to support this or any other figure.
In any event, irradiation is not the only way to exploit markets abroad. The same kind of heat treatment that makes exports of papaya acceptable in mainland markets will soon be available to lychee. Growers of carambola can have access mainland markets through use of a cold treatment approved by the USDA. Canadian markets are another potential outlet for untreated or unirradiated fruit, since Canada has no quarantine against fruit flies similar to that which exists on the mainland.
State officials have themselves expressed concern that widespread irradiation of Hawaiian fruit might allow growers in tropical countries to avail themselves of the same technology, thus eliminating any edge that irradiation might provide to Hawaiian fruit (especially considering the additional ship ment costs of sending fruit from Hawai’i as opposed to Mexico or the Caribbean). “The establishment of post-harvest treatment protocols and irradiation will allow the shipment of Hawai’i fruits and vegetables, but other countries will eventually ask to have those treatment protocols allowed for their fruits and vegetables.”
Finally, it is not clear that there will be strong markets for irradiated produce. Food & Water, a mainland organization, has organized customer protests to stores carrying irradiated fruit, resulting in at least one supermarket chain refusing to stock irradiated Hawaiian produce anymore.
Background
The drawbacks of an irradiation facility may be outweighed by the benefits.
Proponents.
The economic boon that irradiation will provide in Hawai’i more that overcomes any perceived drawbacks. One University of Hawai’i professor of Food Science and Human Nutrition has written, “The issue here, of course, is risk versus benefit. The risks are related to the dangers to the environ ment and the workers … as well as to the dangers of the irradiated foods to the con sumers. The benefits are the economic gains to Hawai’i’s agriculture from the national marketing of Hawai’i-grown exotic fruits…
“There are always risks when handling, storing, or using radioactive materials. How ever, there can also be great risks in handling dynamite, gasoline, or even fire. Yet how many of us daily drive in cars (potential bombs), cook over gas flames or campfires, or light cigarettes with matches (all potential torches)?”19
Opponents
With no analysis of economic benefits having been made public and defended, any discussion of the economic boon of an irradiator is premature, to say the least.
Moreover, in the discussion of risks versus benefits, it is important to bear in mind that people who may not benefit at all will bear at least part of the risk imposed by an irradiation facility. The few employees who may work at an irradiation facility may be willing to tolerate the radiation exposure in return for a wage, but in so doing, they will incrementally increase their own risks of cancer.20 In addition, they will increase the risk that their offspring will be born with genetic damage. These eventualities entail public costs. No matter how safe the developers of any irradiation facility claim it to be, there is no question but that its very presence does impose an incremental risk to the public at large.
Here is what John Gofman, M.D., Ph.D., has to say on the subject. (Gofman is profes sor emeritus of medical physics at the University of California, Berkeley, and one of the leading experts on the health effects of radiation). “First, it is scientifically reasonable that the dose-effect relationship between radia tion and cancer is linear, and that there is no threshold dose… Second, it is a violation of the most fundamental human rights to impose risks (deaths) upon individuals without their consent. Human rights should not be sacrificed to the pursuit of a healthy economy, affluence, progress, science or any other goal. The whole ‘benefits versus risk’ doctrine is a profound violation of human rights.”21
Finally, there is the matter of risk avoidance altogether. “No risk is acceptable if it is avoidable…. However, when people are merely doing a risk assessment, this principle cannot come into play.”22 In the case of a fruit irradia tion facility, any “cost-benefit” or “risk-benefit” assessment must include a discussion of ways to avoid the risk altogether, including alternative treatment methods and the prospect of developing a value-added processed food industry (which has the benefit of increasing the number of jobs).
Background.
Both the state government and the government of Hawai’i County are proposing to spend public money on construction of a fruit irradiation facility.
Proponents
The spending of public money on a project that will directly benefit private growers, and only indirectly benefit the public, is just part of government’s role. The government has a responsibility to see that the economy prospers.
Opponents.
If irradiation is a proven technology (as proponents claim) and the market for irradiated fruit is solid (as proponents claim), there should be no impediment to the private sector raising the capital needed for an irradiation facility, either by putting up the money themselves, by attracting equity investors, or by borrowing the funds. Indeed, this is what capitalism is all about.
In any event, the fruit industry has already received substantial government assistance. The state and federal governments have spent millions of dollars on research into pest control, disease, and other types of quarantine treatments for Hawai’i products. At some point, the subsidies should end.
Background.
Irradiating food requires the use of a high-powered source for the ionizing radiation, which is usually Cobalt-60.
Proponents.
The technology that has been developed for using cobalt-60 as a source for gamma radiation is well established and safe. The American Dietetic Association, for example, states: “Strict regulations govern the transportation and handling of radioactive material. Irradiation facilities are constructed to withstand earthquakes and other natural disasters without endangering the community or workers. Radioactive material is transported in canisters tested to withstand colli sions, fires, and pressure. Worker safety is protected by a multifaceted protection sys tem within the plant.”
Opponents
The history of accidents at irradiation facilities belies claims of their safety. Among the examples of contamination from irradiators is one right here in Hawai’i. In 1967, at a demonstration irradiator at Fort Armstrong, O’ahu, a shipment of cobalt-60 “pencils” corroded through their container, resulting in the leak of radiation from the shipping cask into the water storage pool.
Other examples of unsafe practices at irradiators include incidents at the Isomedix facility in New Jersey, which was determined by the Nuclear Regulatory Commission to have flushed radioactively contaminated water into city sewers in 1974. Another New Jersey irradiator, Radiation Technology, Inc., lost its NRC license in 1986 for repeated worker safety violations. “RTI was cited 32 times for various violations, including throwing radioactive garbage out with the regular trash. The most serious violation was bypassing a safety device to prevent people from entering the irradiation chamber during op eration, resulting in a worker receiving a near lethal dose of radiation.” All these accidents occurred at irradiation facilities using Cobalt 60.
Background.
The state of Hawai’i has signed an agreement that gives it right of first refusal to purchase the seventh unit to be built of a new cesium-137-sourced irradiator.
Proponents.
There are many advantages to using cesium-137 as a source of ionizing radiation. Cesium-137 is abundant as a byproduct of the nuclear weapons manufacturing industry. In contrast to cobalt-60’s half life of about five years, cesium-137 has a half life of more than 30 years, meaning the radioactive source does not need to be replenished as often as a cobalt-60 source. While the storage of cesium salt capsules in cooling pools of water can pose environmental problems, the cesium irradiator considered by the state will not keep cesium in water at all.
Opponents.
Cesium-137 is one of the most dangerous radioactive by-products of nuclear weapons production. Because cesium chloride is water-soluble, when it enters the body, it is distributed to all the cells of the body, creating what is called a whole-body dose.23
As to claims that no radiation can escape thick containment structures, the history of nuclear materials is rife with examples that it regularly does just that. A 1988 accident at Radiation Sterilizers, Inc., in Decatur, Geor gia, brought a halt to the use of Cesium-137 in irradiation facilities. That occurred when “supposedly ‘fail-proof’ cesium-137 capsules leaked into the water storage pool. Officials found ‘extensive’ radiation contamination throughout the facility. In addition, inspec tions of plant workers’ homes and cars found that radioactivity had been transported outside the facility.” Clean-up costs exceeded $47 million.24
Constant bombardment by high-radiation energy, such as would occur in a cesium-137 irradiator, eventually causes the strength of surrounding metal to diminish and the metal to become embrittled. This has occurred in many nuclear reactors vessels and in casks storing high-level nuclear waste (and cesium-137 is classified as a high-level nuclear waste).25
Cesium-137 is stored in capsules that are 21 inches long, 2.6 inches in diameter, and which weigh 20 pounds apiece. A 16-ton stainless steel cask carried on a custom-made trailer bed was needed to transport just 16 cesium capsules when the Department of Energy recalled cesium capsules from a Colorado irradiator in 1994.26
Background.
One of the unresolved issues in any discussion of industry based on nuclear sources is waste. There is no permanent re pository for high level waste in the United States.
Proponents.
Cobalt-60 is not radioactive waste, they say, nor does it generate any. It is deliberately manufactured (by a Canadian firm, Nordion) for use in gamma irradiators, including those used in hospitals as well as private industry. “Radioactive waste does not accumulate at irradiation facilities because no radioactivity is produced…. At gamma irra diators, radionuclide sources, typically co balt-60 or more rarely cesium-137, are used as the sources of radiation energy. These ele ments decay over time to non-radioactive nickel and non-radioactive barium, respectively. The sources are removed from the irradiator when the radioactivity falls to a low level, usually between 6 percent and 12 per cent of the initial level (this takes 16 to 21 years for cobalt-60). The elements are then re turned in a shipping container to the supplier who has the option of reactivating them in a nuclear reactor or storing them. Canada has calculated that all the cobalt-60 it supplied for use in 1988 (about 100 million curies) would require a storage space of about 1.25 cubic meters, roughly equivalent to the space occupied by a small desk.”27
The use of cesium-137 won’t create radioactive waste. It will actually reduce it, since cesium-137, which is now considered a waste, would be converted into a useful commodity. Here is what one investor in the Gray-Star company, which is proposing to build ce sium-137 irradiators, says: “They [Gray-Star] are proposing to ‘privatize’ all of the cesium at Hanford and Savannah River [two of the U.S. Department of Energy nuclear facilities] as a start. One of several scenarios is that the government (DOE) pay them, or their associ ated manufacturer, an appropriate sum of money to take title to the cesium, and remove it from government sites. In effect, this would remove the material from the government’s ‘ledger’ and eventually eliminate the cost and risk of maintaining the isotopes…. Ultimately, the title will be transferred to licensed users within the food industry much in the same way that cobalt-60 is now transferred in normal commerce.”28
Opponents.
Since the production of cobalt -60 does require the use of nuclear reactors, one cannot truthfully say that its production does not generate radioactive waste. All reactors generate high level nuclear waste, for which no safe, long term solution has been found. Cobalt-60 fabrication plants are, in fact, even worse than normal nuclear reactors, being legally permitted to release 20 times more radiation than a commercial reactor.29
In any case, irradiation facilities using co balt-60 do produce radioactive waste. The cooling water in which the cobalt-60 is stored becomes radioactive, as do the containment vessels. These must be handled as radioactive wastes.
As to the statement, that all the cobalt-60 produced in a year could fit in a volume the size of a desk, in theory it might be true; in practice, it isn’t. The total volume required for safe storage of a volume of cobalt-60 the size of a desk is, in reality, many thousands of times that.30
Both cobalt-60 and cesium-137 are highly radioactive for many years. Even when the radioactivity of cobalt-60 has decayed to the point it can no longer generate the high doses of gamma rays needed to irradiate fruit to the USDA-required levels, it still emits radiation at levels too high for humans to be exposed to safely – and will continue to do so for decades.
Cesium-137, with a half-life of 30 years, takes hundreds of years to decay to background levels of radiation. In addition, not only does the use of cesium-137 generate radioactive waste, it is radioactive waste to start with, being produced only as a result of nuclear fission, such as occurs in an atomic explosion or a nuclear reactor.
Proposals such as that of Gray-Star to turn this waste into a private commodity support the arguments of critics who have long main tained that irradiation is part of a plan by the government to reduce its radioactive-waste management costs. DOE’s reason for pro moting nuclear byproducts was made clear at hearings held in 1983 before the House Armed Services Committee: … “the utilization of these radioactive materials simply reduces our waste-handling problem… We get some of these very hot elements like cesium and strontium out of the waste.” The DOE was particularly keen on developing technology to reproduce spent nuclear reactor fuel in order to recover the cesium-137 (and plutonium, although this wasn’t loudly discussed) and it actively promoted the development of food irradiation using cesium-137 for years. According to the DOE in 1983, “The strategy being pursued … is designed to transfer feder ally developed cesium-137 irradiation tech nology to the commercial sector as rapidly and successfully as possible.”31
The accident in Decatur, Georgia, led the DOE to recall all the cesium-137 capsules it had “leased” out and for the irradiation in dustry as a whole to go with cobalt-60 instead of cesium-137. Now that nearly a decade has passed, the DOE – and industry – seem to be attempting to resurrect the idea of cesium 137 as a source for gamma irradiators.
Background.
X-rays can be generated by linear accelerators or other machine source.
Proponents.
The use of a linear accelerator or other X-ray generator avoids the problems associated with use of a radioactive isotope.
Opponents.
To generate X-rays at sufficient strength to meet USDA quarantine requirements, any linear accelerator or other genera tor would almost certainly place a substantial burden on the Big Island’s power supply. This, in turn, might require development of additional energy resources, possibly including geothermal.32 Linear accelerators are rarely used in irradiation facilities, in any event. Without a more detailed proposal for use of an accelerator for treatment of Hawaiian fruit, a pro- and con- discussion is not meaningful.
Background.
Gamma rays and X-rays are used to diagnose and treat health problems. They come from the same types of sources that would be used in a food irradiator.
Proponents.
Since X-rays are used on people, what’s the problem with using X-rays on fruit? This was a point that irradiation’s proponents made often during a town-hall type meeting on irradiation held in Hilo on January 16.
Opponents.
The strength of a radioactive source or electron beam used in an irradiation facility is many millions times greater than that used in medical equipment. The dose that a papaya receives (about 300 Grays, or 30,000 cads, in the process used at Isomedix in Chicago) is one million times the dose that a person would typically receive in a chest X- ray.
For purposes of comparison, the LD 50 dose for humans – that is, the dose sufficient to kill half of an exposed population- is 600 rads. In other words, the radiation that just one papaya must receive is many times that which can kill a person.
- 1. Atomic Industrial Forum, Inc., “20 Questions: An Introduction to Food Irradiation,” September 1986. One of the “distinguished scientists” who reviewed the AIF document is George Giddings, who, in 1986, was director of food irradiation services at the Isomedix plant in Whippany, N.J., and who had done work earlier at Michigan State University “under a contract with the Atomic Energy Commission.”
2. “Position of the American Dietetic Association: Food Irradiation,” Journal of the American Dietetic Association, 96:1 (January 1996), 70.
3. Federal Register, April 18, 1986, p.13378.
4. Letter of Marcia van Gemert, Ph.D., the toxicologist who was chairperson of the FDA review committee in 1982, to New Jersey Assemblyman John Kelley, October, 19, 1993.
5. Donald B. Louria, “Zapping the Food Supply,” The Bulleting of the Atomic Scientists, September 1990, pp. 34-35. Louria is chairman of the Department of Preventive Medicine at the New Jersey Medical School.
6. Richard Piccioni, “Analyses of Data on the Impact of Food Processing by Ionizing Radiation on Health and the Environment,” International Journal of Biosocial Research, Volume 9 (1987), 203-212.
7. Public Citizen Health Research Group, “The Other Side of the Food Irradiation Story” (Washington, D.C., 1986), p.4. The paper cites studies conducted by Ralston Purina Co. for the USDA.
8. ICGFI Fact Series No. 5, published by the International Atomic Energy Agency (Vienna, 1995).
9. American Dietetic Association, op.cit., p.70.
10. AIF, “20 Questions,” p.5.
11. Colby and Epstein, “Risks of radiation: Too many questions about food safety,” USA Today, January 22, 1992.
12. Susan Meeker-Lowry , “From Irradiation to Electronic Pasteurization: Industry Solutions to Unsafe Food,” Z Magazine, May 1996, p.37.
13. AIF, “20 Questions,” op.cit.
14. Donald E. Pszczola, “Irradiated Produce Reaches Midwest Market,” Food Technology (May 1992), p. 90.
15. Statement made at a meeting of the state Agribusiness Development Corporation, September 8, 1995.
16. See Wong’s statement at the ADC meeting of September 8, 1995.
17. Letter of DOA Director Yukio Kitagawa to Rep. Robert Herkes, February 2, 1993.
18. Exotic Pest Insect Committee Budget Proposal for the Fiscal Biennium 1995-1997.
19. Dian Althea Gans, letter of December 22, 1995.
20. Scientists are in general agreement that there is no radiation dose that is so small that it does not pose a danger to any living organism that is exposed to it. Gamma rays and X-rays penetrate skin easily. When they encounter living cells, they can damage chromosomes, which can lead to abnormal cell reproduction, including cancer.
21. Gofman, Radiation and Public Health (San Fransisco, 1981), p.415.
22. “Making Good Decisions,” Rachel’s Environment & Health Weekly, No. 470 (November 30, 1995).
23. Gofman, op.cit., p.51.
24. Quotes are from Meeker-Lowry, op.cit., pp.37-38. The Atlanta Journal/Atlanta Constitution reported the $4.7 million clean-up costs were paid for by the federal government.
25. See, for example, G.L. Edgemon and R.P. Anantatmula, “Hanford Waste Tank System Degradation Mechanisms,” prepared by Westinghouse Hanford Co., for the U.S. Department of Energy. (July 1995). They write: “[L]ong-term, high-energy gamma radiation can produce atomic displacements…Radiation embrittlement of carbon steels results in a reduction in ductility … of the steel.”
26. U.S. Department of Energy, “Transporting Cesium-137”) and “Hanford’s Cesium Capsule Recovery Program Begins”).
27. IGCFI, op.cit., page 28.
28. Letter of Glenn T. Seaborg to Hazel O`Leary, secretary of the U.S. Department of Energy, March 22, 1995. Emphasis in original.
29. Harvey Wasserman and Norman Solomon, Killing Our Own (New York, 1982), p.190.
30. For a discussion of the desk analogy, see Killing Our Own, op.cit., p.197.
31. Meeker-Lowry, “From Irradiation to Pasteurization,” Z Magazine, op.cit., p. 39.
32. This was acknowledged by Mayor Steve Yamashiro in a telephone conversation with Environment Hawai`i on January 7, 1997.
Volume 7 Number 8 February 1997